Certified Rhythm Analysis Technician (CRAT) Practice Exam

To determine the atrial and ventricular rates from the rhythm strip, it’s essential to understand how to calculate these rates based on the number of small boxes in the strip.

The ventricular rate is derived from the R-R intervals, which is the distance between successive R waves. Given that there are 23 small boxes between R-R, the calculation for the ventricular rate is done using the formula:

Rate = 1500 / number of small boxes between R-R.

Thus, for 23 boxes, the rate is calculated as 1500 / 23 ≈ 65.2 beats per minute (bpm), which rounds to approximately 65 bpm.

For the atrial rate, which is calculated from the P-P intervals (the distance between successive P waves), there are 7 small boxes between P-P. The calculation follows the same formula:

Rate = 1500 / number of small boxes between P-P.

In this case, it's 1500 / 7 ≈ 214.3 bpm, rounding approximately to 214 bpm.

Now, looking at the correct answer choice, none of the provided options match the calculated rates of approximately 65 bpm for the ventricular rate and 214 bpm for the atrial rate